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