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