One vertex per element, one color per generator, with an edge from x to x·s.
(1,2)(3,7)(4,8)(5,6)(9,10)(11,15)(12,13)(14,16)(17,18,23,28)(19,30,32,25)(20,34,38,45)(21,40,33,42)(22,29,24,27)(26,37,46,39)(31,47,48,43)(35,44,36,41)(2,6)(7,8)(10,13)(11,16)(17,19)(18,25)(20,35)(21,22)(23,32)(24,33)(26,43)(27,40)(28,30)(29,42)(31,39)(34,41)(36,38)(37,48)(44,45)(46,47) involution — undirected(1,3,5,4)(2,7,6,8)(9,11,12,16)(10,14,13,15)(17,20,22,37,23,38,24,39)(18,26,27,45,28,46,29,34)(19,31,33,36,32,48,21,35)(25,41,42,47,30,44,40,43)(1,4,5,3)(2,8,6,7)(10,13)(14,15)(17,21,24,32,23,33,22,19)(18,25,29,40,28,30,27,42)(20,36,39,31,38,35,37,48)(26,44,34,47,46,41,45,43)(2,6)(7,8)(10,13)(14,15)(17,22,23,24)(18,27,28,29)(19,21,32,33)(20,37,38,39)(25,40,30,42)(26,45,46,34)(31,35,48,36)(41,43,44,47)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.