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