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