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