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