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