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