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