One vertex per element, one color per generator, with an edge from x to x·s.
(1,2)(3,9)(4,8)(5,10)(6,7)(11,16)(12,15)(13,14)(17,18)(19,24)(20,22)(21,25)(23,27)(26,31)(28,29)(30,32) involution — undirected(1,3,7,4)(2,8,6,9)(5,12,14,11)(10,16,13,15)(17,19)(18,23)(20,24)(21,26)(22,27)(25,30)(28,31)(29,32)(33,34)(35,39)(36,40)(37,38)(41,47)(42,45)(43,48)(44,46)(2,6)(8,9)(10,13)(15,16)(21,29)(25,28)(26,32)(30,31)(34,38)(39,45)(40,46)(47,48) involution — undirected(1,4,7,3)(2,9,6,8)(5,11,14,12)(10,15,13,16)(17,20,22,18)(19,24,27,23)(21,28,29,25)(26,31,32,30)(33,35,37,42)(34,39,38,45)(36,43,44,41)(40,48,46,47)(1,5,7,14)(2,10,6,13)(3,11,4,12)(8,15,9,16)(17,19)(18,24)(20,23)(21,26)(22,27)(25,31)(28,30)(29,32)(33,36,37,44)(34,40,38,46)(35,41,42,43)(39,47,45,48)(1,6,7,2)(3,9,4,8)(5,13,14,10)(11,16,12,15)(17,21,22,29)(18,25,20,28)(19,26,27,32)(23,30,24,31)(33,34)(35,39)(36,40)(37,38)(41,47)(42,45)(43,48)(44,46)A Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.