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