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